NEW YORK — Women with ovarian cancer and diabetes who took the generic diabetes drug metformin showed better survival rates than those who did not take the drug, according to a new study led by the Mayo Clinic.

The study, published in the journal Cancer, enrolled 61 patients who took metformin and 178 who didn't. Of those who took the drug, 67% were surviving after five years, compared with 47% of those who didn't take it. Further analysis indicated that patients taking metformin were almost four times likelier to survive than those not taking it.

"Our study demonstrated improved survival in women with ovarian cancer that were taking metformin," study co-author and Mayo Clinic gynecologic oncology fellow Sanjeev Kumar said. "The results are encouraging, but as with any retrospective study, many factors cannot be controlled for us to say if there is a direct cause and effect. Rather, this is further human evidence for a potential beneficial effect on a commonly used drug [that] is relatively safe in humans."

The researchers said the results could pave the way for using metformin in large-scale trials in women with ovarian cancer.